The service is free, but may not be of much use for some AT&T customers because it comes with a big caveat: You need a phone that supports AT&T HD Voice (iPhone 6s and 6s Plus, SE, 7, and 7 Plus) and you must be in an HD Voice coverage area. That covers about two thirds of the United States, but for people outside HD Voice coverage areas—which includes most of Colorado, Utah, New Mexico, Nevada, Idaho, Oregon, Montana, and Nebraska—Call Protect won’t work regardless of which phone model you have.

Despite the HD Voice limitations, AT&T’ senior vice president of Device and Network Services Marketing Jeff Bradley sees the service as a valuable tool. “Nuisance calls are an industry-wide problem that unfortunately affect many people,” hw said. “We’ve listened to our customers and know they want a network that provides tools to proactively assist in blocking nuisance calls.”

You can enable Call Protect in the myAT&T app on your iPhone, but it’s easier to first download the free Call Protect companion app from Apple’s App Store. The app enables and disables the service, and lets you control call blocking settings, too.

Call Protect’s App Store reviews are mixed at best. Many are complaining that the setup process failed, which wasn’t a problem when The Mac Observer set it up on one of our test iPhones. Others are complaining the service doesn’t seem to be working, which could mean those users are outside AT&T’s HD Voice coverage areas. Regardless, the initial response to the Call Protect app has been pretty poor.

Why in the hell isn’t the login my phone number and password. Ya have to use a MyATT account. Either that or as Bob Forsberg says block the robo-calls at the highest level, license/approve legitimate numbers from the kid’s school, emergency services and such.